<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="../react18/react.development.js"></script>
    <script src="../react18/react-dom.development.js"></script>
    <script src="../react18/babel.min.js"></script>
</head>

<body>
    <div id="app"></div>
    <script type="text/babel">
        class App extends React.Component {
            state = {
                count: 0
            }
            render() {
                const { count } = this.state;
                return (
                    <div>
                        <button onClick={handle}>+</button>
                        <p>{count}</p>
                    </div>
                )
            }
        }
        function handle() {
            alert(1)
            // 事件函数并不是当前绑定事件的DOM调用的,事件函数是默认调用的,事件函数中的this默认指向undefined
            console.log(this);
        }
        const root = ReactDOM.createRoot(document.getElementById('app'));
        root.render(<App />)

    </script>

</body>

</html>